Poultry paws, the portion of the leg below the feather line, have three principal grades, condemned grade, sub-grade, and A grade. Condemned grade paws are used primarily as a component in animal feeds. Sub-grade and A grade paws are used principally for human consumption. The principal market for poultry paws for non-animal food purposes is in Asia. The difference in price per pound between condemned grade paws and sub-grade or A grade paws can range from 400 to 800%. Therefore, it is commercially advantageous to minimize the number of paws that are classed as condemned grade. Similarly, it is desirable to maximize the number of paws that are classed as A grade.
One of the principal factors which can cause a paw to be graded below A grade is the presence of dark sores on the paw. In chickens, these sores or lesions often are urea burns that arise from contact between the chicken and its own feces. In the prior art, certain methods have been used to prevent the ammonia burns from occurring, including treating the chicken houses with ammonium bisulfate or dilute phosphoric acid in order to reduce the corrosive nature of the ammonia present. Bacterial treatment of the ammonia has also been used. These methods are all preventative in nature. The inability to remove the dark clotted blood associated with these lesions after they have formed often results in the paw being ground into cat food.
Another factor which can result in the down grading of poultry paws is color. Demand for white paws far exceeds the demand for black paws because of consumer perception that is apparently not founded in any objective taste, texture or nutritional characteristic of the paw. Unfortunately for poultry processors, several commercially significant chicken varieties have black paws, substantially all of which are currently sold solely as condemned grade.
A third factor that can result in a condemned grade is deformities of the paw. Of the three factors discussed above, it is the only one which cannot be at least partially treated by the method disclosed herein. Fortunately, deformed paws comprise less than ten percent of the annual chicken paw crop.